Characterization of Softmagnetic Thin Layers Using Barkhausen Noise Microscopy

Abstract

Ferrnmagnetic materials are essential for data recording devices. For inductive or magnetoresistive (MR) sensors softmagnetic thin layer systems are used. Optimal performance of these layers requires homogeneous magnetic properties, especially a pronounced uniaxial magnetic anisotropy. Furthermore, microstructural imperfections and residual stresses influence the magnetic structure in the layer system. Barkhausen Noise Microscopy enables the characterization of such thin layers. By cycling the magnetic hysteresis of ferromagnetic material electrical voltages (the Barkhausen noise) are induced in an inductive sensor. Miniaturization of the sensor and the scanning probe technique provides resolution down to few micrometers. Two materials were examined in terms of their structure, thickness, residual stresses and heat treatment condition: Sendust, used in inductive sensors and nanocrystalline NiFe, used in MR-sensors. In quality correlations to Barkhausen noise parameters were found. For representative sample a quantification of residual stress distribution could be established employing X-ray stress analysis.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2001
Accession Number
ADP012284

Entities

People

  • Iris Altpeter
  • Jochen Hoffmann
  • Norbert Meyendorf

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Coercivity
  • Diffraction
  • Domain Walls
  • Ferrites
  • Ferromagnetic Materials
  • Hardness
  • Magnetic Fields
  • Magnetic Materials
  • Magnetic Properties
  • Materials
  • Measurement
  • Mechanical Properties
  • Microscopy
  • Nondestructive Testing
  • Residual Stress
  • Stresses
  • X Rays

Readers

  • Materials Science and Engineering.
  • Structural Dynamics.